Cooling of aircraft engines



March 29, 1938. J. LLOYD 2,112,727

. JOQLING' OFAIRCRAFT ENGINE S Filed. Nov. 11, 1956 2 Sheets-Sheet '1 .Fig. 1.

v JZnyL Z0365 March 29, 1938. J LLOYD 2,112,727

COOLING OF AIRCRAFT ENGINES Filed Nov. 11 1956 2 Sheets-Sheet 2 mum/70;

' Jkv 50 25 4770/P/VEX2 Patented Mar. 29, 1938 UNITED STATES PATENT ,OFFlCE Application November 11, 1936, Serial No. 110,357

In Great Britain August, 30, 1935 4 Claim;- (01. 244-551 This invention relates to the cooling of aircooled aircraft engines, such as have their crankshafts arranged longitudinally of the aircraft,

, whether of the in-line, star, or other types. The main object is to cool the engine adequately and at the same time to reduce drag.

According to one feature of the invention, the outlet end of the engine cowling is connected to transmit the cooling air into or through the inlo terior of a wing of the aircraft which has at least one outlet, which may be controllable in size, in or near its trailing edge, or in its upper surface where the air pressure is relatively low.

When the engine is mounted in the nose of i5 the fuselage and is enclosed in a cowling open at the front and back, the rear opening may be connected by a duct or duets with the interior of a wing. This hollow part of the wing is open at its trailing edge, so that the cooling air issues a there into the eddy which already exists behind the trailing edge.

A flap may be used at the outlet to control the air flow; and if arranged at the trailing edge of a wing, the flap may serve as an air brake or 25 lifting flap.

The invention further involves, in the case of a cowled air-cooled engine mounted in the'wing of an aircraft, forming the inlet orifice of the cowling as a horizontal slot.

In the accompanying drawings, which are diagrammatic:

Figure 1 is a fragmentary sectional plan of an aeroplane having an air-cooled star-type engine mounted on a wing and arranged according to the invention, Figure 2 being a cross-section taken on the line lIII of Figure 1;

Figure 3 is a fragmentary sectional plan of an aeroplane having an air-cooled star-type engine mounted in the nose of the aeroplane body and 49 arranged according to the invention;

Figure 4 is a fragmentary sectional plan of an alternative method, according to the invention, of arranging an air-cooled star-type engine in the nose of an aeroplane body, Figure 5 being a 5 detail sectional view taken on the line V-V of Figure 4; and

Figure 6 is a fragmentary sectional plan of an aeroplane having an in-line, star, air-cooled engine mounted on a wing and arranged according to the invention, Figure 7 being a cross-section taken on the line VH-VII of Figure 6 and Figure 8 being a. front view thereof.

Like numerals indicate similar parts throughout the drawings as far as possible.

In the construction of Figures 1 and 2, the engine H is mounted on the wing |2-the chain line in Figure 2 represents what the section of the wing would be at the line 11-11 of Figure 1 if the wing were continuous there. The engine is surrounded by an annular cowling l3 which 5 is faired into the wing, the cowling directly communicating at its rear end with the interior of the wing so that all the air entering the cowling and flowing past the engine is directed into the interior of the wing. An outlet opening it is pro 1o vided in the trailing edge of the wing and this is shown in the drawings as being controlled by a pivoted flap I5 movement of which varies the outlet opening and thus the amount of cooling air flowing past the engine. The flap in question 15 may be used as an air-brake if desired.

In the arrangement of Figure 3, the rear end of the cowling is directly connected to the leadlug-edges of the wings on opposite, sides of the body, and a bulkhead I 8 is provided in the latter to cause the cooling air to travel into the interior of the wings, whence it can be evacuated through controllable slots asdescribed in connection with Figures 1 and 2.

In the modification shown by Figures 4 and-5, the bulkhead I6 is extended laterally, into the wings, as indicated at H, to cause the air to travel outwardly along the wings to a greater extent than in the modification of Figure 3, and in the construction of Figure 4 the air is released through the openings between the trailing edge of the, wings and the ailerons l8.

In the construction of Figures 6 to 8 the engine is a fifteen-cylinder one of star form, but with the cylinders arranged in'flve, lines each of three cylinders. Internal baiiles I9, I! are disposed between each adjacent pair of lines. In this construction, moreover, the inletv orifice an to the cowling i3 is in theform of a horizontal oval opening or other slot.

'lhus the disturbance of the air round the usual cooling air outlet, which is just behind the engine cowling, is avoided and the total drag of the aircraft is thereby reduced.

What I claim as my invention and desire to secure by Letters Patent of the United States 1. In an aircraft structure, a hollow supporting wing, a cowling having its front end open and its rear portion communicating with the interior space of the hollow wing, an air-cooled engine housed entirely within said cowling and having space between the engine and the cowling for the circulation of air received through the front open end of the cowling and having a propellet forwardly'of the open end of the cowling, saidairhackwardlythroughthe cowlins and into the hollow wing,saidwlnghaving at its rearmosttrailingedgeandinthelowerpartof saidedgeanopeningforthemcapeofthecoolingairintotheeddyexisflngbehindthetrailing edge,andacombinedvalvemeansand aileron ingbeingabovesaidvaivemeanswherebythe exhaustcoolingairisbroughtoutalongthespace above the upper face of the combined air brake havingatitstraillngedge at-oppuile sidsofsaidbulkheamsaidopeningsbeingin ofaaidopeningswherebytheexhaustcoolingair isbroughtoutalongthespaceabovetheupper facesofthecomlinedairbnkesorliftlngflaps.

3.1nanaircraftconstruetimahollowwlng, acowlinghavingitsrearportionconnectingwith said wing and interiorly communicating withthe interiorspaeeofthewing,saidcowlinghavinga front open end, an air-cooled engine mounted entirelvinsaidcowlingatflieforwardportion thereofwithspacearoundtheenginewithinthe cowling for thee of currents of cooling air and having a propeller forwardly of the open end of the cowling, a bulkhead having a rounded nose insaidhollowwingandprojectingpartiallyinto the rear portion of the interior space of the cowlingv for diverting the air currents from the cowling in the opposite dde portions of the wing, said bulkhead having lateral extensions lying within the opposite side portions of the wing and spaced from the front wall of the wing, said hollow wing having openings at the lower side of its rear trailingedgefortheeseapeofthecoolingair intotheeddywhichalreadyexistsatthetraiiing edge of the wing, and combined flap valves and ailerons pivoted at their forward end portions in said openings for opening and closing said openings and varying the port area thereof, said flap valves movable downwardly to open saidandatthesametimeserveasair brakesosrliftingflaps, said openingsbeing above the flap valves. said flap valves being pivoted at theloweredgesofsaidopeningswhereby the exhaustcoolingairisbroughtoutalongthespace above the upper faces of the flap valves induc- "ing considerable atmospheric rarity and eddying aboveandbehindtheilapvalves.

4.Inanaircraftconstruotion,ahollowwlng,

acowiinghavingafrontopenendwith itsrear portionopeningintosaidhollowwing,anair cooled engine mounted entirely in said cowling,

saidenginecomposedofrowsofeylindersspaced apart radially, baile plates interposed between and extmdingrearwardlyofsaid rowsof cylinders and partition of! the space between the cylinders into separate chambers through which thecoolingairmaypasasaidwinghavingan openingatitstrailingetkmandacombined 'Jomw mom. 

